For most men, the thought of getting kicked in the testicles represents the height of fear. If you’ve ever been kneed or kicked or socked in the groin, you know that it gives a particularly disquieting form of pain. And yet, wherever there is a pain there is also a masochist to embrace it, and thus being kicked in the balls has slowly entered into the standard repertoire of practices that you can pay for at any house of domination. And when you consider some of the other forms of genital torture — piercing, cutting, splitting — that people practice nowadays, being kicked in the nuts doesn’t even sound that bad.